Oxidative metabolism of bovine spermatozoa

1968 ◽  
Vol 46 (10) ◽  
pp. 1331-1332
Author(s):  
J. F. Masken ◽  
M. L. Hopwood
Keyword(s):  
Oxygen Consumption ◽  
Citric Acid ◽  
Melting Point ◽  
Oxidative Metabolism ◽  
Phosphate Buffer ◽  
Citric Acid Cycle ◽  
Specific Activity ◽  
Acid Cycle ◽  
Bovine Sperm ◽  
Bovine Spermatozoa

Suspensions of washed bovine sperm (phosphate buffer, pH 7.4) were incubated at 37 °C for 1 h with pyruvate-3-14C and in some cases, with oxaloacetate. Oxygen consumption and 14CO2 evolution were measured. Radioactive citrate, malate, fumarate, α-ketoglutarate, and oxaloacetate were found following incubation. The latter two compounds were positively identified by melting-point and specific-activity determinations of their 2,4-dinitrophenylhydrazone derivatives. The results indicate citric acid cycle activity in bull sperm. Oxygen consumption and the evolution of 14CO2 from pyruvate-3-14C tended to decline when oxaloacetate was added to the sperm suspensions.

Use of a single 13C NMR resonance of glutamate for measuring oxygen consumption in tissue

1999 ◽  
Vol 277 (6) ◽  
pp. E1111-E1121 ◽  
Author(s):  
F. Mark H. Jeffrey ◽  
Alexander Reshetov ◽  
Charles J. Storey ◽  
Rui A. Carvalho ◽  
A. Dean Sherry ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Oxygen Consumption ◽  
Citric Acid ◽  
Magnetic Resonance ◽  
Citric Acid Cycle ◽  
Single Measurement ◽  
Acid Cycle ◽  
Nmr Data ◽  
Rat Hearts ◽  
C Nmr

A kinetic model of the citric acid cycle for calculating oxygen consumption from13C nuclear magnetic resonance (NMR) multiplet data has been developed. Measured oxygen consumption (MV˙o 2) was compared with MV˙o 2 predicted by the model with 13C NMR data obtained from rat hearts perfused with glucose and either [2-13C]acetate or [3-13C]pyruvate. The accuracy of MV˙o 2 measured from three subsets of NMR data was compared: glutamate C-4 and C-3 resonance areas; the doublet C4D34 (expressed as a fraction of C-4 area); and C-4 and C-3 areas plus several multiplets of C-2, C-3, and C-4. MV˙o 2 determined by set 2(C4D34 only) gave the same degree of accuracy as set 3(complete data); both were superior to set 1(C-4 and C-3 areas). Analysis of the latter suffers from the correlation between citric acid cycle flux and exchange between α-ketoglutarate and glutamate, resulting in greater error in estimating MV˙o 2. Analysis of C4D34 is less influenced by correlation between parameters, and this single measurement provides the best opportunity for a noninvasive measurement of oxygen consumption.

ENERGY METABOLISM OF PHYCOMYCES BLAKESLEEANUS THE CITRIC ACID CYCLE AND ASSOCIATED AMINO ACIDS

1966 ◽  
Vol 12 (1) ◽  
pp. 1-4 ◽  
Author(s):  
Edwin C. Gangloff
Keyword(s):  
Amino Acids ◽  
Citric Acid ◽  
Energy Metabolism ◽  
Organic Acids ◽  
High Activity ◽  
Citric Acid Cycle ◽  
Specific Activity ◽  
Nitrogen Compounds ◽  
Phycomyces Blakesleeanus ◽  
Acid Cycle

All of the intermediates of the citric acid cycle are shown to be present in the mycelium of 6-day cultures of P. blakesleeanus grown on glucose and on ammonium sulfate, and fed non-radioactive acetate on the fourth and fifth days and acetate-1-C14 on the fifth day of incubation.The concentration of organic acids and certain amino acids, and their specific activity is reported. The high activity of the latter is thought to indicate the presence of a highly labeled pool of nitrogen compounds persisting from the early anabolic reactions after acetate-1-C14 administration.

Effect of growth substrate on enzymes of the citric and glyoxylic acid cycles in Thiobacillus novellus

1971 ◽  
Vol 17 (5) ◽  
pp. 617-624 ◽  
Author(s):  
A. Michael Charles
Keyword(s):  
Citric Acid ◽  
High Speed ◽  
Citric Acid Cycle ◽  
Nadh Oxidase ◽  
Specific Activity ◽  
Glyoxylic Acid ◽  
Growth Substrate ◽  
Malic Dehydrogenase ◽  
Aconitate Hydratase ◽  
Acid Cycle

A quantitative study was conducted of enzymes involved in the citric acid cycle and associated systems of the facultative autotroph Thiobacillus novellus grown on five different substrates. Irrespective of the growth substrate the organism possessed complete citric and glyoxylic acid cycles and the specific activity of α-ketoglutarate dehydrogenase was always quite low. Also, the activities of the enzymes of both cycles were usually lowest in extracts from autotrophic cells, and highest in extracts from acetate-grown cells. The three remaining extracts had activities that were between the two extremes with those from glucose-grown cells generally lower than those from pyruvate and succinate. Several exceptions should be noted among these generalizations. For example, the activity of aconitate hydratase and malic dehydrogenase was lowest in extracts from glucose-grown cells while that of isocitric dehydrogenase was lowest in extracts from pyruvate-grown cells. Transhydrogenase activity was virtually absent from extracts of pyruvate- and succinate-grown cells while NADH oxidase, which was identical in these two extracts, was also relatively low. Of interest is the large amount of cytochrome c found in high-speed supernatants. In extracts from autotrophic cells this was about 2.3% of the soluble protein and is suggestive of a significant role being played by the electron-transport system during growth of the organism.

EFFECT OF SERUM GONADOTROPHIN ON DEHYDROGENASES OF THE CITRIC ACID CYCLE IN THE OVARY OF THE RAT

1963 ◽  
Vol 42 (4) ◽  
pp. 480-484 ◽  
Author(s):  
B. Eckstein ◽  
R. Landsberg
Keyword(s):  
Citric Acid ◽  
Citric Acid Cycle ◽  
Age Groups ◽  
Succinic Dehydrogenase ◽  
Immature Rat ◽  
Acid Cycle ◽  
Immature Rats ◽  
Rat Ovary

ABSTRACT The succinic, malic and isocitric dehydrogenases in the ovary of immature and mature, normal and serum gonadotrophin injected rats were examined. The Qo2 of these enzymes were markedly enhanced in the gonadotrophin injected rats of both age groups, except in the case of succinic dehydrogenase in the ovary of the immature rats, where a slight non-significant decrease was noted. It is concluded that in the mature rat ovary, gonadotrophin administration stimulates the activity of all the examined dehydrogenases of the citric acid cycle, whereas in the immature rat ovary, at least the isocitric- and malic dehydrogenases are thus stimulated.

Sign in / Sign up

Export Citation Format

Share Document